Boiler furnace



May 9, 1933. s. w. ALLEN BOILER FURNACE Filed Oct. 8, 1950 16 .1. 132.4. 0 12 .9 I 15 a2 ii Zg INVENTOR 1 W U1 A'ITORNEYS,

Patented May 9, 1933 UNITED STATES PATENT OFFICE s mmer w. ALLEN, ,or.waawrcx, mronn ISLAND, ASSIGNOR TO DRAKE NON:

CLINKERING FURNACE BLOGK COMPANY, 1110., ornnw YORK, N. Y., A coaroma;

TION OF NEW YORK BOILER FURNACE Lpjlieati on filed October 8, 1830.Serial No. 487,180.

This invention is a novel boiler furnace,

having especial reference'tothe water tube type of boiler having one ormore baffles causing the products of combustion to travel successivelythrough the passes of the boiler, and the furnace being fired in variousways for example by stoker or by the burning of injected or fluent fuelas a flame.

The general objects of the invention are to improve the operation andthe efficiency of such a furnace and boiler and to reduce themaintenance cost thereof. A further object is to afford, in a practicalmanner, a bridge wall beneath the bafiie, which bridge Wall is watercooled, and to afford at the same time an effective slag screen betweenthe combustion chamber and the boiler. Further and more specific objectsand advantages of the invention will be pointed out in the hereinafterfollowing description of an illustrative embodiment thereof or will beunderstood by those conversant with the subject.

To the attainment of such objects and advantages the invention consistsin the novel boiler furnace and the novel features of operation,combination, arrangement and structure herein illustrated or described.

In the accompanying drawing Figure 1 is general side elevation of theelements of the boiler furnace of this invention, with the front wall,rear wall, bridge wall and baflles shown insection.

.Fig. 2 is a section taken on the inclined line 2--2 of Fig. 1 lookingfrom the front and with certain parts broken away.

Fig. 3 is a vertical section taken on the line 33 of Fig. 2.

Fig. 4 is a view corresponding to a por- I tion of Fig. 1 but showingthe combustion chamber fed with fuel by an injector or burner ratherthan by a stoker.

As will appear more in detail the present construct-ion comprises thewater tube boiler with its higher header at what will be termed thefront of the furnace and its lower header at the rear, with a bafliewall extending through the boiler, and a bridge wall below the baflle,the bridge wall comprising a system of ascending water tubes and meansclosing the spaces between the tubes, with downward tubes or connectionsbringing water to the lower ends of the bridge wall tubes and extensiontubes connecting from the upper ends of the bridge wall tubes to theboiler.

The drawing indicates side walls 5, front wall 6 and rear wall 7 allsupported on suitable foundations. As the indication is onlyillustrative, and to some extent diagrammatic, it'will be understoodthat the sizes, proportions and illustrated arrangements may be variedindefinitely in accordance with the type of boiler and furnace to whichthe invention is applied.

In Fig. 1 the invention is shown applied to a stoker fired furnace.Exterior to the front wall 6 is a coal hopper 8 and therebelow coalinfeeding means conventionally indicated at 9. The grate 10 may be ofthe retort type into the retorts of which the coal is underfed. The fuelbed for example may buildup along the dotted line 11 and as the bedtravels progressively toward the rear the burned out fuel is dumpedintermittently orcontinuously by a dumping grate 12 into an ash pit 13.

Instead of the stoker and coal feeding arrangements as shown in Fig. 1,the furnace maybe fired by pulverized coal, or other fluent fuel, suchas oil or gas; and in Fig. 4: the front wall 6 is shown as provided witha series of apertures, each containingv an inecting means or burner 10by which the fluent fuel is injected into the combustion space toproduce flames, in a well known manner, to traverse the combustion spacefind thence travel through the passes of the o1 er.

The boiler is composed mainly of inclined.

. ond bafile 21, so that the boiler is divided into three passes, theproducts finally traveling upwardly and to the usual stack.

The bridge wall 22 is arranged below the main baffle and is showncomposed of water tubes 23 adapted to absorb radiant heat and effectevaporation, and wall closing elements 24, which may be continuedupwardly to meet the lowerend of the baffle as continued downwardly at,25 beyondthecombustion chamber, these extensions being led out from theash pocket through openings in the. rear wall thereof and connected up-to-=a common header 26 located at an exterior point protected from theheat ofv the furnace and ash pocket. From the lower end ofthe boilerheader 19, and therefore fed by downtakes 18,. is a system of. downtakesv 27, conducting water to the header. 26 and thereby supplyingwater for circulation through the bridge wall tubes 23.:

An advantageous structure is 7 shown wherein the header 26 between;:thetubes,

and; tubes 27 is supported in a stirrup 28' which in turnis suspended bya resilient device 29 having means 30 for adjusting the height of theheader. By this arrangement the bridge wall isin a substantiallyfloating condition at its: lower end, expansion and contraction beingallowed for by theadjust-ablerand resilient mounting-of the low.- erheader. The curvatures ofthe tubes. 23 and 27 cooperate in this yieldingaction of the bridge wall.

Preferably 'all of the bridge wall tubes 23. deliver into anupper header31, which is shown alsoin Figs. 2 and 3, and may beef. squareform. Asystem of shielding menr, hers. or blocks 32 is shown at the fire sideof; the-header 31, protecting it from excessiye heat, andjthis shieldingmeansmay be composed of cast iron with or without refractory inserts, orany other material giving adequate protection to the header and theconnection of the tubes therewith. From the upper bridge wallheader 31is shown a series of tubes 33 and 34: extending at a forward and upwardslant to the front of the boiler, for example to the lower end. of thefront boiler header'15.

An advantageous construction is shown wherein the upper header 31 issolidly mounted andmay'beconsidered as a. support from whichthe bridgewall depends andiupon. which the baflie may to some extent .besupported. This construction. is

The

shown in Figs. 1 to 3 and involves at each end of the header 31 a saddleor support 35 solidly mounted within a recess 36 in the side wall 5. Bythis arrangement the entire bridge wall is substantially hung orsuspended from its upper end; Itis supported firmly at the top end andhangs down preferably into the ash pit in the case of a stokerfurnace.

The contour of 'thefbridge wall. of

special'desi'gn. It: extends upwardly from the lower end and then slantsor curves rearwardly at a decided incline from the center of.combustion. This permits the upper header 31 to be located at a pointfar removedfrom thecenter of combustion. Additionally this" header isprotected by an interior shield. In effect the tubes 23, 33 and 3% passto an exterior orprotected; point where'they are connected by theheader.

Thelower header 26 islikewise protected atan exterior location; Thebridge wall tubes extending up from: the lower header arespaced fairlyclosely asindicated in Fig. 2, whereas the downcomers 27 are preferablyspaced at least twice as widely and indeed there may be few downcomers,across the width of the furnace, so long astheir total capacity willconduct all water required for circulation throughth'e tubes23;

[Thebridg'e wall tubes 23' are shown bare, but they may have Ia facingor covering so long asit'i's of'a high heat conductive character. Itisintended that the bridge wall shall absorb large quantities of radiantheat, which is carried off by evaporation in the tubes 23, thus bothincreasing evaporation and protecting the wall.

The spaces between the tubes 23 are closed in any suitable manner, forexample-by refractory or metallic closing, members either at thefront,.or as shown at the rear, of the tubes. The manner of. the closureof the bridgewall is a detail and it may. be by fins or. extensions ofthe tube. v

Thetubes 33 and 34 extending from the upper header 31 to the'frontof theboiler,

or to the boiler header 15, are preferably separated orv spaced. intotwo rows, as well shown in Figs. 1. and 2., These tubes areshorter thanthefull lengthboiler tubes and they extend across the topof thecombustion.

space- They are spaced from each other twice as widely as the; spacingof theboiler tubes, as seen.in Fig. 2'. 'Fhis arrangement gives theeffect? of a slag screenwith; tworows of; widely spaced-tubes. Such slagscreen protects the boiler from. slaggin'g. The tubes receive radiantheat so that m'oliten ash particles: are cooled andsolidified beforepassing; into the-boiler. The two rows of tubes may; enter-the front.boiler header. at

two levels, but preferably they are bent near eachx'end, as shown,so'that'both rows-1 enter.

the header at the same level, just as they enter the header 31 at thesame level.

The described structureis a combination which gives the advantages of awater cooled bridge and of a slag screen between the combustion spaceand boiler. These results are obtained in a simple and practical way.The invention is well adapted to be introduced upon existing boilerssince the connections to both the front and rear headers of the boilerare allowed for merely by omitting the usual lowest row of boiler tubes.

It will thus be seen that a boiler furnace has been described attainingthe objects of this invention. Since many matters of operation,combination, arrangement and structure may be variously modified withoutdeparting from the principles of the invention, it is not intended tolimit the inven tion to such matters except to the extent set forth inthe appended claims.

What is claimed is:

1. In a boiler furnace, a water tube boiler having a higher front and alower rear header, front, side and bridge walls enclosing the combustionchamber below the front portion of the boiler, an ash pit below the rearportion of the combustion chamber, a baille wall extending through theboiler above the bridge wall, a system of water tubes comprised in thebridge wall, upper and lower headers therefor, extension tubes from theupper header to the front of the boiler, and downtakes from the rear ofthe boiler to the lower header; the bridge wall being supported fromabove and hangs ing into the ash pit, and the tubes of the bridge wallbeing continued through and from the ash pit to an exterior pointwhereat is said lower header.

2. In a boiler furnace, a water tube boiler having a higher front and a.lower rear header, front, side and bridge walls enclosing the combustionchamber below the front portion of the boiler, an ash pit below the rearportion of the combustion chamber, a bafiie wall extending through theboiler above the bridge wall, a system of water tubes comprised in thebridge wall, upper and lower headers therefor, extension tubes from theupper header to the front of the boiler, and downtakes from the rear ofthe boiler to the lower header; the bridge wall being supported fromabove and hanging into the ash pit, and the tubes of the bridge wallbeing continued through and from the ash pit to an exterior pointwhereat is said lower header, and means for yieldingly supporting thelower header.

3. In a boiler furnace, a water tube boiler having a higher front and alower rear header, front, side and bridge walls enclosing the combustionchamber below the front portion of the boiler, the bridge wall continuedinto the boiler as a baflle, fixed walls enclosing an ash pit below therear portion of the combustion chamber, a system of uptake water tubescomprised in the bridge wall, an upper header therefor and extensiontubes from the upper header to the front of the boiler; the bridge wallbeing supported from above and hanging into the ash pit, and its watertubes being extended slidingly through the rear fixed wall of the ashpit for downward expansion thereof, and having an exterior lower header,and downtakes from the boiler to said lower header.

4. In a boiler furnace, a water tube boiler having a higher front and alower rear header, front, side and bridge walls enclosing the combustionchamber below the front portion of the boiler, the bridge wall continuedinto the boiler as a baffle, fixed walls enclosing an ash pit below therear portion of the combustion chamber, a stoker delivering to the ashpit, a system of uptake water tubes comprised in the bridge wall, anupper header therefor and extension tubes from the upper header to thefront of the boiler; the bridge wall being supported from above andhanging into the ash pit, in overlapping relation to the fixed rear wallof the ash pit, and the bridge wall water tubes being continued belowsuch overlap and extended slidingly through the rear fixed wall of theash pit in a downward direction, for expansion thereof through suchwall, and such tubes having an exterior lower header, and downtakes fromthe boiler to said lower header.

5. In a boiler furnace, a Water tube boiler having a higher front and alower rear header, front, side and bridge walls enclosing the combustionchamber below the front portion of the boiler, an ash pit below the rearportion of the combustion chamber, a system of water tubes comprised inthe bridge wall, extension tubes from the upper ends of said tubes tothe boiler, means supporting the bridge wall and its tubes from above tohang into the ash pit, and the lower ends of the tubes being connectedby a header adapted to descend with expansion, and vice versa, aresilient means yieldingly positioning such lower header, and a downtakefrom the boiler to said lower header.

In testimony whereof, this specification has been duly signed by:

STUART W. ALLEN.

